PREPARATION AND NONLINEAR OPTICAL PROPERTY OF POLYDIACETYLENES FROM UNSYMMETRICAL DIPHENYLBUTADIYNES WITH TRIFLUOROMETHYL SUBSTITUENTS
In order to obtain the polydiacetylenes having ?-conjugation between polymer backbone and side chains, many of unsymmetrical diphenylbutadiyne derivatives with trifluoromethyl substituents on one of the phenyl rings have been synthesized.Among them, 1-(3-(methylamino)phenyl)-4-(3,5-bis(trifluoromethyl)phenyl)butadiyne (MADF) was found to be topochemically polymerized with complete conversion into the polymer single crystals.Spectroscopies and X-ray crystal structure analysis revealed that the ?-conjugation of this polymer are more extended than those of the sofar prepared poly(diphenylbutadiyne)s, with smaller dihedral angles between ?-conjugation planes of polymer backbone and phenyl rings.The extended ?-conjugation was also confirmed by larger χ(3) values.